## Drinking games and digital logic

For those of you who might have forgotten, let’s go over the rules of Centurion. The object of the game is for every minute, for 100 minutes, drink a shot of beer. It doesn’t sound like a lot, but after completing the challenge you’ll have had 3 liters of beer (or about eight and a half 12 oz cans) in just under two hours. When [Peter] played Centurion, he found the biggest problem was – understandably – keeping track of the time and who drank what. For an upcoming weekend of drinking, [Peter] decided to solve this problem once and for all with shift registers and seven-segment displays.

[Peter]‘s Centurion score box comes in two parts. The first and largest part of the build is the main board housing an ATMega8 microcontroller and a huge two digit seven-segment display to keep track of the countdown until the next shot. Two other boards house eight additional two digit seven-segment displays for each player, incremented every time a player presses a giant arcade button.

The entire build is designed around a small travel case that also holds a large battery for cordless drinking parties. Let’s just hope the project is reasonably water-resistant; we can see a lot of spills happening in the future. Check out the video demo below.

## Clock display taller than you is just what your living room has been missing

Sure, it’s time to get the countdown clocks ready to ring in the new year, but why limit it to just one night? If you end up building a six-foot digital display you can count down trivial events; like the remaining seconds of freedom before you have to pimp yourself out in that drab cubicle.

This seven-segment display is homemade and boasts six full-sized digits and two smaller digits with each pair separated by colons. You have probably already guessed that the construction was greatly simplified by using LED strips rather than individual components. This is part of the reason for the size of the display. The strips can be cut, but only down to a minimum of 3 LEDs per segment. That explains the small digits, with their larger siblings doubled in size. But there is a benefit to this constraint, it means that current limiting is already taken care of for you.

The main assembly is a wooden frame surrounding two polycarbonate sheets. The LED strips are sandwiched between those sheets, with segment and digit driver buses exiting a one point on the side. The build doesn’t detail a driver for the display but it shouldn’t be hard to find a multiplexing example that will serve the purpose.

## CMOS logic clock tracks 24-hour time

Here’s an IC logic project that displays 24-hour time. Planning was the name of the game for this project. [Mattosx] took the time to layout his design as a PCB in order to avoid the wiring nightmare when build with point-to-point connections.

Much of the complexity is caused by the display itself. Each of the six digits has its own binary-coded decimal chip and array of discrete resistors. Timekeeping is handled by six decade counters, two divider chips, one AND gate chip, and one OR gate chip. He chose a SOIC crystal oscillator chip as the clock signal. We’re more partial to the idea of using mains voltage as the clock signal.

[Mattosx] posted the board artwork if you’d like to etch your own 5″x8″ PCB. Just make sure you read through all of his notes as not all of the chips are oriented in the same direction.

[via Reddit]

## Puncher tracks your freelancing hours, time spent in TSA patdowns

[Raphael Abrams] does a lot of freelance work, but he has trouble accurately keeping track of the hours he has put in for his clients. After trying various applications and methods of logging his time, he finally decided to build a device that worked just the way he liked.

He calls his device the “Freelance Puncher”, though it already has been nicknamed the detonator, as it looks like something you would find in the hands of a [James Bond] villain. The device uses a PIC16LF1827 to track the time, saving his logged hours to the built-in EEPROM when powered off. A pair of 7-segment displays are used to display the accumulated hours upon power-on, and a set of seven SMT LEDs separated into two banks keep track of quarter and hundreds of hours worked.

[Raphael] has made his code and schematics available on Github, so you can easily replicate his work if you are looking for a better way to track your time. We think it looks great, though it could be the sort of thing that traveling freelancers might want to keep in their checked luggage, unless they want to spend some quality time with the TSA! Be sure to stick around to see a short video where [Raphael] shows off and explains how his Freelance Puncher works.

## A simple, self-contained 7-segment display

It’s no secret that seven-segment displays are an easy and useful way to relay data, so [Kelvyn Panici] decided to put together a minimalst, self-contained display for use around the house.

The display itself is a 16-digit model he picked up from DealExtreme for under \$10. He wanted to find a microcontroller small enough to fit behind the display’s footprint, so he chose an ATtiny85 to control it. After mounting the mcu on a small piece of perfboard, he burned the Arduino bootloader and uploaded a small sketch to drive the display.

Things worked out quite well as you can see by the video below where he shows off a pre-perfboard prototype. [Kelvyn] currently does not have any immediate projects in the works that will utilize the display, though there are a plethora of possibilities. We think it would work great anywhere if it were fitted with a battery and some sort of wireless radio in order to make it completely self-contained.

## Going RGB with 7 segment displays

We can order seven segment displays in red, green, yellow, or blue all day long. One thing we haven’t seen is an RGB segmented display, so [Markus]‘ project is really interesting. He took a stock seven segment display and modded it into an RGB display.

After taking a Dremel to the back of the stock display, [Markus] was left with a seven segment light mask. A few SMD LEDs were purchased through the usual channels. The RGB LEDs were epoxied into place on the back of the light mask one at a time. Thankfully, the LEDs came with magnet wire already attached – helpful, since these LEDs are only 1.6mm x 1.2mm big.

With 32 pieces of magnet wire, [Markus] needed some sort of socket. A small piece of perfboard and some .100″ headers handled the job very nicely. [Markus] still has to work on some way to drive the 24 cathode lines his LED display. He’d like an I2C interface, but with something like an individual seven segment display, the footprint of the circuit should be pretty small. If you’ve got any tips, drop them in the comments section. [Markus] is sure to catch them there.

## Keeping tabs on your pets’ busy lives

[Stephen’s] daughter has a pair of mice she keeps as pets, who happen to be quite active at night. After they kept her awake for an entire evening by running like mad in their treadmill, they were moved from her bedroom. Since they were so active in the treadmill, [Stephen] thought it would be cool to try measuring how much the mice actually ran each night.

To keep track of their activity, he built a simple circuit that records how many rotations the treadmill makes. He fitted it with a rare earth magnet, installing a reed switch on the outside of case that ticks off each spin of the wheel. Any time the wheel starts moving, his PIC begins counting the rotations, displaying them on a 7-segment LED display. To mitigate data loss in the event of a power outage, the PIC stores the current number of rotations in its EEPROM every 10 seconds or so.

The counter keeps track of the total number of rounds the mice have completed, which his daughter uses to manually calculate their running sessions. Since they started tracking the mice, they have run over 700,000 rounds, sometimes completing as many as 20,000 in an evening.

We think it’s a pretty cool project, especially since it makes it fun for his daughter to stay involved in her pets’ lives.